Enabled "fsl,legacy-bch-geometry" in U-Boot device tree overlay
to match the legacy BCH geometry layout, which mainline Linux
applies when "fsl,use-minimum-ecc" is not specified in the device
tree.
Reinstated SYS_NAND_ONFI_DETECTION, which when disabled, masked
the mismatch on SOMs with Winbond NAND flash chips.
Signed-off-by: Niel Fourie <lusus@denx.de>